An image forming apparatus that employs an electrophotographic system well-known in the art includes a cartridge that stores developer.
As such an image forming apparatus, Japanese Patent Application Publication no. 2000-250310 discloses a printer that can detachably accommodate a process cartridge therein. The process cartridge includes a drum cartridge having a photosensitive drum, and a developing cartridge for storing toner that is detachably attachable to the drum cartridge.